1. Field
One embodiment of the invention relates to an image processing apparatus, a display device, and an image processing method.
2. Description of the Related Art
Filtering has been performed with an edge-preserving smoothing filter to remove noise, such as mosquito noise and block noise, from an image. A bilateral filter is known as an edge-preserving smoothing filter. While the bilateral filter can achieve sufficient edge smoothness, it is not suitable for high-speed operation because of a large operation amount. For example, Japanese Patent Application Publication (KOKAI) No. 2008-153812 discloses an ε filter as a conventional edge-preserving smoothing filter suitable for high-speed operation. Using a threshold ε, the ε filter applies filter smoothing to a portion where shading change due to noise is below the threshold ε to remove the noise. With this, the operation amount can be reduced.
The ε filter as described above realizes a edge-preserving smoothing filter suitable for high-speed operation, but it cannot achieve sufficient edge smoothness as is achieved by the bilateral filter.